The Arkansaw traveler., 1887-07-23
Complied for The Arkdnsdw TrGueLer. SCIENTIFIC MISCELLANY.

Weak carbolic acid solution, sponged over head and hair, is said to drive away any and all insects.
 In one district of Algeria, 50,O0O gallons of grasshoppers' eggs have been collected and burned this year.
 Paper, or other fibrous form of eel. lulose, passed through bath of nitric acid, and then washed, becomes eellu- vert, new material of great tough ness.
 From an examinat ton of butter from various parts of France, NJ. E. Du- claux learns that, contrary to general opinion, the quality of this article depends largely on the breed of cattle and their food, the pasture-eoil, inf1u- ence of season, age of milk, etc.
 By means of mixture of pulver- ized magnesium, chloride of potash and sulphide of antimony, Messrs. Goldicke and Miethe produce an ex- plosive, lightning like illumination, which is likely to be of much value in photography. The flash lasts one- fortieth of second, and provides a cheap and practical method of secur- ing instantaneous pictures at night or in dark places.
 A CHEMICAL MILEsToNE.-The dis covery ofa new gas is a rare and i'm portant event to chemists. Such a discovery has been announced in Ger many by Dr. Theodor Curtius, who has succeeded in preparing the long sought hydride of nitrogen, amidogen, diamide, or hydraZine, as it is vari- ously called. This remarkable body, which has hitherto batfled all attempts at isolation, is now shown to be gas, perfectly stable up to a very high temperature, of a peculiar odor differ ing from that ofammonia, exceedingly soluble in water, and of basic prop critics. In composition it is nearly identical with ammonia, both being compounds of nitrogen and hydrogen.
 ASTRONOMICAL OBsERvAToRIEs -
 Very ancient observatories are said to have been erected on the top of the temple of Belus, at Babylon on the tomb of Osymandyas, in Egypt; and at Benares. The first in authentic history was erected by Ptolemy Soter at Alexandria, about 300 B. c. Of prominent modern observatories the dates are: French Royal, 1867 :; Greenwich, 1875; Nuremburg, 1878 ]; Utrecht, 1890; Berlin, I'll Bologna, 1714; St. Petersburg, 1725; Pekin, about 1750; Oxford, 1772 Edin- burgh, 1776; Dublin, 17s3 Armagh, 1793; Cambridge, Eng, 1924; Will Hams college, first in the United States, 1886; Pulkowa, 1889; Cam bridge, Mass, 1840; Washington, 1S42; Liverpool, lS44; Ann Arbor, 1854; Albany, 1856. The Lick ob- servatory in California, equipped with the largest retractor yet made, was en- dowed with $700,000 in 1874.
 MAKING A SEA.-During many years spent in Tunis, Colonel Rou- daire surveyed four great depressions, or "shotts," extending below sea level in such position that they may be filled with water by means of canal. These depressions - named Teded, Djerid, Rharsa and Melrir-could thus be changed into a lake more than seventy-five feet deep, and having an area of 3,l64 square miles. The crea- ton of this lake and the consequent improvement of much surrounding country formed the favorite project of Colonel Roudaire, and now seems likely to be accomplished in spite of its authors death. The artesian wells tried in the district, and from which revenue in aid of the canal was ex- pected, are proving successful. The first well, sunk in 1885 to depth of 295 feet, commenced yielding water at the rate of 1,760 gallons per minute, and has now increased its flow to 1O,- 800 gallons per minute. According to Sir F. de Lesseps, the banks of the river Melah, which fifteen months ago were deserts, are now populated; and very shortly the canal will be com- menced.
 THE ATLANTIC WINTER.-A series of semi-diurnal weather charts for the north Atlantic, from November 8, 1882, to February IA, 1883, has been issued by the Meteorological Council of Great Britain, and supplements similar series which has been prepared to show the weather of the summer and autumn months. A striking diff ference in the two series is given by the more disturbed character of the winter, and the great range of air pressure at that season. The high ba- rometer reading of 30 to S0.3 inches, which extends over most of the north Atlantic in summer, is attended to the northward by low area of 29.2 to 29.5, the depression usually being too